1. Field of the Invention
The present invention relates to liquid crystal display (LCD) technology, and more particularly to a GOA (Gate Driver on Array) circuit for LCD applications and LCD devices.
2. Description of Prior Art
In recent years, GOA technology has started to be applied to a manufacturing process of LCD display panels, and it has replaced the original manufacturing process, which originally used external integration circuits (IC) as a means to implement a driving function for horizontal scanning of LCD display panels by forming driver circuits on the circumference of a display area of a substrate. GOA technology is able to reduce the amount of external ICs and packaging procedures such that the costs of flat panel displays can be reduced. At the same time, a narrow-bezel panel that has features such as being lightweight, thin, and a symmetrical look can be carried out and a more compact display module is advantageous due to the possibility of simplifying the design of the drain driving circuits, the increased resolution of a display panel, and the application in flexible display panels.
The existing GOA circuits typically include multiple cascaded GOA units, and each GOA unit corresponds to driving one-stage horizontal scanning line. The GOA unit includes a pull-up circuit, a pull-up control circuit, a transferring circuit, a pull-down holding circuit, and a bootstrap capacitor. The pull-up circuit is mainly responsible for outputting a gate (Gate) signal which is used for driving GOA circuit by inputting a clock pulse sequence (Clock) and using a control circuit to control a timing of the activation of the pull-up circuit. The pull-up control circuit is usually connected to a transfer signal or a Gate signal delivered from a preceding-stage GOA unit. The pull-down circuit is responsible for pulling down the Gate signal to be configured in a low electric potential at the first timing segment, namely, the Gate signal is turned off. The pull-down holding circuit is responsible for maintaining the Gate output signal and a Gate signal point (commonly referred to as “Q point”, hereinafter called as “key node Q”) of the pull-up circuit in negative electric potential. Furthermore, a bootstrap capacitor is used for secondarily lifting a voltage of the Q point to be instrumental to the gate output of the pull-up circuit.
Even though the existing GOA circuits have adopted the design of three-segment voltage division in the pull-down holding circuit, the stability problems of the GOA circuits that are especially caused by the stability of circuit components is still a big issue in display devices. On the other hand, there are diverse needs for scanning means of a display apparatus.